public class java0713 {
    public static void func(IShape iShape){
        iShape.draw();
        if(iShape instanceof Cycle2){
            Cycle2 cycle2 = (Cycle2) iShape;//向下转型，此时就能调用Cycle2中的方法了
            cycle2.find();
        }
    }

    public static void main(String[] args) {
        func(new Cycle2());
    }
}
